Electromagnetic vibratory interrupter



Feb. 20, 1940. l. M. SLATER ELECTROMAGNETIC VIBRATORY INTERRUPTER Filed Dec. 10, 1936 2 Sheets-Sheet 2 ATTORNEY Feb. 20, 1940. M. sLATER ELECTROMAGNETIC VIBRATOIr INTERRUPTER Filed Deo. lO, 1936 2 Sheets-Sheet 1 :NVENTOR ra/7. .Slder m ATTORNEY Patented Feb. 20, i940 UNITED STATES PATENT OFFICE VIBRATORY INTER- l. R. Mallory & Co.,

Inc., Indianapolis, Ind.,

a corporation of Delaware Application December 10, 1936, Serial No. 115,171

d Claims.

This invention relates to electromagnetic vibratory devices such as are used in voltage supply circuits and the like.

An object of the invention is to improve such vibratory devices.

Other objects of the invention will be apparent irom the following description and accompanying drawings 'taken in connection with the appended claims.

The invention comprises the features or construction, combination of elements, arrangement of parts, and methods of manufacture and operan tion referred to above or which will be brought out and exemplined in the disclosure hereinafter set forth, including the illustrations in the draufm ings.

in the drawings:

Figure i is a side elevation of a vibrator and the grounding cup therefor;

Figure 2 is a bottom view of the assembly or' Figure l;

Figure 3 is a section on the line i-of Fig ure l;

Figure i is a longitudinal section or' the vibrator;

Figures 5 and 6 are perspective views of the sound and vibration insulating members of the vibrator;

Figure 7 is another longitudinal section of the vibrator;

Figure 8 is a section on the line i--il oi? Fig- Figure 9 is a section on the line oi. Figure 7 Figure l is an exploded vievr of parts of the vibratory reed and contact assembly of the vibrator; and

Figure ll is a diagrammatic view of one circuit in which said vibrator may be used.

W'hile a preferred embodiment of the invention is described herein, it is contemplated that considerable variation may be made in the method of procedure and the construction o'parts without departing from the spirit of the invention. In the following description and in the claims, parts Will beidentied by specic names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

Referring to the drawings the vibrator comprises a metal can Il enclosing the operating parts of the unit, the can il preferably being extruded or drawn from a single piece of metal, such as zinc or cadmium, although other metals, for example, iron can also be used. The end i 2 of (Cl. 20o-90) can il is tapered in thickness, the thinnest portion being at the center and the thickest portion at the edges. This materially reduces the diaphragmatic radiation from the end of the can v'when the Vibrator is in operation.

At the other end i3 of can Il is a disc I4 of sheet insulating material, such as sheet Bakelite, in which are mounted the connecting prongs i of the vibrator. Disc i4 is provided with an ear or lug i9 which extends through a co-operating opening near the end of. can Il, the end i3 being turned over the edge of the disc at a point opposite lug it to secure the disc in place. lf desired the end i3 of the can may be spun cr crimped over disc it around the entire periphery.

A grounding cup l5 nts over the end iii of can ii with its prongs il pressing against the sides of the can in electrical contact therewith. 'in mounting the vibrator for operation it is preferred that the grounding cup it be secured against and in contact with a hat metal panel or chassis by rivets or screws passing through holes it in the ground cup and With the connecting socket for the vibrator located in the central opening of the cup. The vibrator can then be inserted into the grounding cup it with prongs i5 in the connecting socket, the grounding cup serving as a mechanical support for the vibrator and also providing a low-impedance path to ground for any high-frequency static or hash .developed by the opening and ciosing of, the Vibrator contacts.

The vibrator unit Within can li is enclosed within sponge rubber sheaths 2l! and 2l for purposes of sound and vibration suppression. Sheath 2D is a generally rectangular hollow cup of molded sponge rubber having a projecting boss it extending out from the middle of its closed end and a pair of beveled ridges 23 extending along two opposite sides, respectively, adjacent the open end of the sheath. When sheath 2D is inserted in the can i l the boss 22 rests against the center of end i2 of. the can and ridges 23 against the inside cylindrical Wall of the can.

Sheath 2l comprises a double-ended cup of molded sponge rubber exteriorly of generally cylindrical shape and having recesses 25 (Figure 6) and 26 (Figure 7) in the respective ends thereof. The opposite sides of sheath 2l are beveled, as at 3|, to increase the spacing from the' Wall of can Il.

-When the vibrator is assembled the vibrator unit, comprising the electromagnet 28, vibratory reed 29 controlled thereby, the contacts cooperating with the reed and the frame supporting these parts and securing them together in cooperating relation, is held within the closed chamber formed by recess 25 in sheath 2| and recess 21 in sheath 28, the ends of sheaths 20 and 2| being held together by the end walls of the can.

This arrangement affords a kind of cantilever suspension for the sheaths and the vibrator unit inside it thereby allowing considerable freedom of vibration of the end portion 24 of the assembly within the can li without transmitting the vibrations to the can to any great extent.

Suitable perforations are made in dividing Wall 30 in sheath 2| to accommodate the conductors 64 which connect the vibrator unit to the prongs l5.

The electromagnetic vibrator unit within the .Y sponge rubber sheathscomprises frame 32 formed of a. at bar of metal of high magnetic permeability, such as iron, bent into what might be termed a rectangular hook shape so as to provide an elongated shank portion 33, a short transverse portion 34 at one end of the shank portion, and

a short reverse portion 35 at the outer end of the transverse. portion, the reverse portion 35 being parallel or substantially parallel to the shank portion 33. The shank portion 33 and transverse portion 34 are preferably, although not necessarily of equal width and thickness but the reverse portion 35 is preferably considerably narrower than the other portions so that the coil 28 may be conveniently fitted over it. The single piece frame and core member adapts itself to precision manufacture, so that very little individual adjustment of the units is required.

Coil 28 is a winding of insulated wire on a bobbin 36 comprising a single molded piece of insulating material such as Bakelite. The central opening in form 36 is just sullcient in size to fit over reverse portion 35 of the frame with v a snug-nt so that the reverse portion comprises the core of the coil. If necessary the'endyor pole 31 of reverseportion 35 may be enlarged slightly after the coil form is in place by hammering or pressure to lock the coil form in place. With the coil mounted on the reverse portion in the manner described the magnetic variations caused by current variations in the coil are concentrated and made most effective at the pole of the core where they may be effective in controlling the reed.

The free end of shank portion 33 of the frame 32 is reduced slightly in thickness to provide an accurately planed flat surface 38 against which rests one end of a stack 39 of operating parts and spacers including an end of reed 29 and its co-operating contacts. The stack is held to the frame by the pair of stack screws 48 passing through the shank portion 33 of the frame and held by nuts 4l.

The stack 39 (starting at face 38 of the frame) comprises a thick metal spacer 42 threaded to receive the two` stack screws 49, an insulating sheet spacer 43 of fibre, ceramic, mica, mica substitute, synthetic resin, anodized aluminum or other suitable material, a pair of contact springs 44 and 45 mounted side by side over respective insulating -bushings 6I, a pair of stop arms 46 and 41 individual to the contact springs 44 and 45 respectively and similarly mounted, an insulating sheet spacer 48, a metal plate 49, end of reed 29, metal plate 58, contact shim 59, insulating sheet spacer 5l, stop arms 52 and 53, contact springs 54 and 55 individual to arms 52 and 53,

'the sides of the stack and insulated wires 64 are soldered at one end to these lugs and at the other end to prongs I5 of the unit. -A shim may also connect adjacent stop arms, such as 52 and 53, l

together (and thereby their associated contact` A Wire may connect one of the' spring). stop arms (and itsassociated spring) with one end of .the winding of coil 28, the other end of the winding being grounded to frame v32 (thus being'connected to the reed through jumper iii). Spring plate 58 may be of spring steel having a concave-convex bias about a longitudinal axis so that when screws 48 are tightened intoposition a constant compression .will be applied to the stack 39 and any tendency to loosen after extended use will be overcome. Lock washers also may be provided beneath nuts 4I, if desired.

It will be understood that variations can be made in the stack assembly. For example, shims may be inserted at various places to adjust the spacing. Likewise, in some instances, `the end of shank 33 of the frame may be extended by a transverse lug to make contact with the base of reed 29 to improve the magnetic path between the frame and reed. This can also be accomplished by providing a transverse lug on metal plate 42 provided it is of magnetic permeable material, or by bending an extended portion of the reed down against the frame. l

Reed 29 comprises a strip of thin spring metal, preferably of magnetically permeable material such as steel, and has a pole piece 66 of magnetic permeable material, .such as iron, riveted or welded to its free end. The free end of the reed v is offset with respect to pole 31 of the electromagnet (formed by coil `28 plus the frame 32) so.t hat a magnetization of the electromagnet will attractl the reed pole piece and draw the reed in the direction of contact springs 54 and 55. Pole piece 66 is comparatively heavy with respect to the stiffness and mass of the reed assembly so that it largely dominates the reed vibration.

A pair of metal stampings 61 and 68 are riveted to opposite faces of reed 29 by rivets 69 which pass through both stampings and the portion of the reed located between the clamped and free end thereof, relatively nearer the clamped end. Stampings 61 and 68 each carry a pair of integral tongues 13, 1I and 12, 13 respectively which are spaced from the reed and whose ends are substantially parallel to the reed and extend toward the free end thereof. A contact disc 14 is secured to the outer face of each tongue at the end thereof. Contacts 14 are preferably of tungsten or the like. While they may be of considerable thickness, as shown, it may in some instances be desirable to make them very thin, for example, of a thickness in the order of 0.02 inch. An advantage in using the thin tungsten discs on the contact springs resides in their light weight which introduces less inertia deflection in the portions of the springs beyond the stop arms. The springs thus have less tendency to bounce away from the stop arms during operation.

Reed 29 is provided with a transverse slot or opening 15 between its clamped end and the portion where the stampings 61 and 88 are secured. This slot greatly increases the flexibility of this part of the reed, thus greatly improving the starting characteristics of the vibrator since less magnetic pull is required to close the contacts than would be necessary without the slot.

A second opening 16 is provided in reed 29 between the place where the stampings are secured and the free end of the reed. Opening 16 is tapered in width; being widest near the free end and tapered to a rounded point near the central portion of the reed. This controls the stiffness of the reed so that its stiness near the stampings is greater than near the pole piece. As a result of this the curvature of the reed during vibration will be approximately constant over a considerable length instead of being greater at one point than at another. This produces approximately uniform fibre stress throughout most of the ilexing portion of the reed so that breakage is reduced. Hole 16 also reduces the sound radiation of the reed which would otherwise resuit due to diaphragm action and reduces the air load on the reed. This reduction in air load enables the reed to vibrate at higher speeds with greater stability and less damping during operation. Likewise greater contact pressures will result and the amplitude of the reed vibration will be increased.

Contact springs 44, 45, 52 and 53 each carry a contact disc 11 near their ends and positioned as to comoperate with contacts 14 on the reed tongues.

in some instances as where contact springs 45 and 55 are connected in the primary circuit of a potential changer system and springs 44 and are in the secondary, or high potential circuit, the spring :l and 55 may be thinner than springs dfi and 54 the extra space being made up in the stack by shims individual to the thinner springs. provides greater contact pressure on the springs it and 54 so that the contact is improved in the high potential circuit. Other means could also be used to provide different stiffness in certain ci the springs.

springs 44, 45, 52 and 53 are each bent at 'slight angle along a line 18 at a. point that lies beyond the edge of the stack not more than one-third the exposed length of the stop arms.'

The bends 1c are shown somewhat exaggerated Figure i0. When the springs are clamped in the stack their outer regions lie flat against the stop, as shown, for example, in Figure 8. The

spring has substantially no tendency to bounce during operation. In order to provide greater contact pressure on the rectliier (or high potential) contacts the bend can be made somewhat greater for these contact springs so that their initial pressure against the stop arms is greater. This expedient can be used either with or without the thicker springs described above.

in operation the vibrator unit can be used in any of the customary potential changer circuits of the prior art such as that shown in Figure 3 of Patent #2,049,310. In this circuit each of con tact springs M, 45, 54 and 55 is in a separate branch of the circuit.

According to another arrangement the contact springs #it and i5 are connected together (as by a bridging shim in the stack) and contact springs 54 and 55 are similarly connected together so that each pair is, in effect, a single contact except for the obvious advantage of lower resistance and less chance of erratic contact where dual contacts are used. This parallel contact arrangement provides an interrupter such as could be used for primary circuit interruptions only, where the secondary current is rectified by some form of rectifying device. Figure 11 is a circuit diagram showing parts of such a circuit.

According to a modication of the structure herein described only one contact spring may be provided on each side of the reed and a single contact will then be attached to each side of the reed to co-operate therewith.v The contacts, in this instance, will be centered with respect to the reed. This provides a structure adapted for use in a primary interrupter circuit of the type just described.

The vibrator structure disclosed provides a very fast contact break during operation due to the provision of stop arms 46, 41, 52 and 53 and the mounting of contacts 14 on tongues 10, 1I, 12 and 13. This materially reduces the arcing at the contacts during break.

Vibrators according to the present invention can be made of very small size, ior example, in the order of 11/2 inches in diameter and 3 inches long.

While the present invention, as to its objects and advantages, has been described herein as carried out in specic embodiments thereof, it is not desired to be limited thereby but it is intended to cover the invention broadly within the spirit and scope oi the appended claims.

What is claimed is:

l. An electromagnetic vibratory interrnpter comprising a frame, an electromagnet coil mounted on one end thereof and a vibratory reed mounted on the opposite end thereof and having its free end extending toward the first mentioned end of said frame, electrical contacts controlled by the vibration of said reed, said frame consisting of a continuous piece of magnetically permeable material having an elongate shank comprising the main body of the frame, a transverse portion integral with one end of said shank and transverse thereto and a reverse portion integral with the outer end of said transverse portion and substantially parallel to said shank with its free end extending toward the opposite end thereof, said coil being mounted on said reverse portion so that the free end of said portion comprises a pole of the electromagnet thereby produced, the free end of said reed being disposed adjacent the free end of said reverse portion and a pole piece thereon of magnetically permeable material whereby said reed is controllable by said electromagnet.

2. An article of manufacture consisting of a mechanical interrupter unit for a 'potential changer adapted for use with a direct current source as the B supply of a radio receiver, said unit comprising a base formed of a single piece of magnetic permeable material having an elongate shank, a transverse portion integral with one end of said shank and a reverse portion integral with the outer end of said transverse portion and having its free end extending toward the other end of said shank, a magnetic coil mounted on said reverse portion, a vibratory reed of magnetic permeable material mounted on said other end of the shank, said vibratoryreed having the major portion of its body disposed substantially parallel to the axis of said reverse portion with its free end extending toward the free end of said reverse portion to constitute one pole of said magnetic coil.

3. As an article of manufacture, a mechanical interrupter comprising an elongated base formed of a single piece of magnetically permeable material bent into a rectangular hook shape so as to comprise an elongated shank, -a transverse portion integral with and substantially perpendicular to one end of said shank and a reverse portion integral with the outer end of said transverse portion and extending toward the other end of said shank with its axis disposed substantially parallel to said shank, a magnetic coil mounted on said reverse portion whereby said portion comprises the core for said coil, an elongated vibratory reed mounted on the last-mentioned. end of said shank with the major portion of the body thereof disposed substantially parallel to the axis of said core andthe free end thereof disposed adjacent to and offset from the free end of said core.

4. As an article of manufacture, a mechanical interrupter comprising an elongated base formed of a single piece of magnetically permeable material bent into a rectangular hook shape so as to comprise an elongated shank, a transverse portion integral with and substantially perpendicular to one end of said shank and a reverse portion integral with the outer end or said transverse portion and extending toward the other end of said shank with its axis disposed substantially parallel to said shank, a magnetic coil mounted on said reverse portion whereby said portion comprises the core for said coil, an elongated vibratory reed of magnetically permeable material mounted on the last-mentioned end of said shank with the major portion of the body of said reed disposed substantially parallel to the axis of said core and the free end thereof disposed adjacent to and offset from the free end of said core for movement substantially transversely of the axis of said core whereby the free end of said reed constitutes one pole of said magnetic coil.

5. A vibratory motor comprising, in combination, a frame formed of a continuous piece of material bent into a rectangular hook shape and comprising an elongated shank, a transverse portion integral with one end thereof and substantially perpendicular thereto and a reverse portion integral with the outer end of said transverse portion and extending toward the other end of said shank with its axis substantially parallel thereto, a magnetic coil mounted on said reverse portion and a vibratory reed secured to said other end of the shank and extending toward the free end of said reverse portion.

6. A Vibratory motor comprising, in combina tion, a frame formed of a continuous piece of magnetic permeable material bent into a rectan gular hook shape and comprising an elongated flat shank, a transverse portion integral with one end thereof and substantially perpendicular thereto and a reverse portion integral with the outer end of said transverse portion and extending toward the other end of said shank with its axis substantially parallel thereto, a magnetic coil mounted on said reverse portion whereby said portion comprises the core for said coil and said coil and core form an electromagnet, and a vibratory reed secured to said other end of the shank and extending to a position for co-operation with said electromagnet.

IRA M. SLATER. 

